Battery Backup Sump Pump Installation
Answers on dual-pump basins, battery maintenance, and check valve placement for a sump pump that keeps working when the power goes out.
The Basement Watchdog Combo Preassembled Primary & Battery Backup Sump Pump System w/Monitoring Controller (CITE-33); Copper-Wound PSC Motor
BASEMENT WATCHDOG
A sump pump’s one job is to run during the worst storm of the year — which is exactly when the power tends to go out. A battery backup is what closes that gap, but only if it’s installed and maintained correctly. Here are the direct answers to the questions that decide whether your basement stays dry.
A pre-assembled backup pump combo takes the guesswork out of the battery and switch pairing.
The Basement Watchdog Combo Preassembled Primary & Battery Backup Sump Pump System w/Monitoring Controller (CITE-33); Copper-Wound PSC Motor
BASEMENT WATCHDOG
- System comes preassembled and preplumbed so that installation is simple and quick
- Reliable design with durable ⅓ HP energy efficient copper-wound Permanent Split Capacitor (PSC) motor for long life and…
- Primary pumps 62 GPM (3,720 GPH) at 0 ft lift; 51 GPM (3,100 GPH) at 10 ft. to quickly empty the sump pit
- Backup pumps 42 GPM (2,500 GPH) at 0 ft lift; 25 GPM (1,500 GPH) at 10 ft. to quickly empty the sump pit
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Frequently Asked Questions
Q: Do I need a battery backup sump pump?
A: If your primary pump runs during storms and your area loses power, yes. A storm that dumps rain and knocks out electricity is precisely when a sump pump fails, and a finished basement or valuable storage makes that risk expensive. If you have a whole-house generator, you may be covered instead.
Q: How does a battery backup sump pump work?
A: It sits in the same basin, either beside the primary pump or stacked above it, and runs off a deep-cycle battery. When the primary pump can’t keep up or loses power, the backup activates automatically. Most use a separate float switch mounted slightly higher so it only triggers when the primary falls behind.
Q: What size battery do I need?
A: A deep-cycle marine or AGM battery rated around 75–100 amp-hours. That typically provides a few hours of continuous pumping, which covers most outages. The bigger variable is pump volume — a higher-capacity pump drains the battery faster.
Q: How often should I replace the backup battery?
A: Every 3–5 years, even if it hasn’t been used. Batteries lose capacity as they age, and a four-year-old battery may deliver far less than its rated runtime right when you need it most. Test the backup system quarterly.
Q: Where does the check valve go, and why does it matter?
A: The check valve sits in the discharge pipe above each pump and prevents water that’s already been pumped out from flowing back down into the basin. Without one, the pump re-pumps the same water over and over. The backup pump needs its own check valve so the two pumps can’t back-feed each other.
Never run a backup sump pump off a standard car battery. Car batteries are designed for short, high-current bursts, not the deep, sustained discharge a sump pump needs — they’ll die quickly and can’t handle repeated deep cycling.
Q: How do I test my backup sump pump?
A: Once a quarter, unplug the primary pump (or lift its float) and pour a few gallons of water into the basin to confirm the backup kicks on and pumps it out. Also check the battery terminals for corrosion and top up distilled water on flooded-cell batteries.
